Nissan QashQai Forums

Nissan Qashqai J11 uses intelligent battery charging system - IPDM (Intelligent Power Distribution Module), which if car battery is fully charged, should keep it ready at full charge with trickle charge current which equals to voltage on battery terminals around 13,2V. Vice versa, if the battery charge status drops down, IPDM increases charging current, which will result in higher battery voltage at maximum 14.5V in order to avoid damaging battery cells.

The table below shows what voltage (on open terminals) equals to electrolyte density (applicable for Pb and EFB lead acid batteries) and charge capacity:

Idle [V]..............Electrolyte [g/cm3]........Charge
12,6.........................1,26 - 1,28.................100%
12,40 - 12,54..........1,24 - 1,25...................75%
12,24 - 12,40..........1,21 - 1,24...................50%
11,88 - 12,18..........1,13 - 1,18...................25%
11,88 - less.............1,12...............................0%



I made a video during my 11.5 hours lasting journey, IPDM kept charging the battery insufficiently, holding the charge at about 50% of its capacity i.e. 12.37V at above 2000 rpm. Now the car has been parked for several days left untouched and the battery voltage is down to 12.20V which is less than 30% of its capacity. When the battery is not charged enough, the cells start to sulphate, which cause irreversible damage to the battery - decreasing its capacity, shorted cells, etc. If I would start the car now, it will charge the battery with high current and the voltage on battery poles will be 14.47V. Few minutes later, charging current will decrease and the battery voltage get steady at 12,37V again. I don't know whether this was intention when Nissan designed the car, but it definitely is not OK.

I have already had one battery replaced under warranty after 8 months of use (FIAMM) but I guess this will not last longer either. Has Nissan realized this? I don't think so....

PS
Important to mention that the voltmeter I have connected to the power socket has been calibrated with METEX-3850 with tolerance +/- 10mV. Idle current that flows through the voltmeter is 3mA only so I keep it connected at all times in order to screen the charging system and the battery charge status.

My battery (FIAMM) failed to turn the engine over a couple of days ago and I had to call out the RAC to start the car. Stop/Start fail also indicated.
The RAC said the battery was shot and required replacement. The Nissan service centre thought otherwise and kept the battery a couple of days using a smart charger and reported the battery was now OK and refitted it on the car.
They could not explain why the battery failed in the first place and I now have no faith in the battery not letting me down again.
My driving profile is long runs and I always turn off the Stop/Start so the battery has an easy life.
Any ideas on how to proceed with getting the battery replaced under warranty?

I strongly believe the battery you have is faulty, as I had the same problem with FIAMM battery among the others. Time will tell, then keep us informed.

Following the dealers reluctance to change the Battery I contacted Nissan Customer Service.
It was a complete waste of time. They couldn't explain why I had a problem or why the RAC recommended a Battery change but they wouldn't authorise the dealer to change the Battery unless I paid for a replacement.
To head off future problems I now use my own Smart Charger every week to keep the Battery from letting me down.
Not a satisfactory outcome.

My battery went flat despite using every day. Car is only 18 months old and with all my previous cars I have never had a flat battery for at least 40 years. Is there a problem ?

It indeed seems there is a problem. I thought it has got somehow self fixed after I fully charged the battery out of the car. It was fine for a week only. In order to keep lead-acid battery in good condition and at its full capacity, "variable voltage charging system" should be equalized to 13.2V when it is fully charged and not below 12.5V (discharged below 80%).

You can plug Voltmeter in to the power socket (under the dash board) and monitor how your charging system works.

I had this on a J10 2012, 1.6 dCi. just went dead over night they replaced the faulty battery .

Interesting, I will check mine the next time I'm out and about but the stop start seems to work most of the time so can I take this as an indicator that the battery is ok?

Suggested that leaving car with out locking can drain battery. Checked today - with door locked battery was V 12.22 Unlocked car and V fell to 12.08V so some draining is taking place. Will continue my investigation

Interesting

Only had my QQ a couple of weeks, but as its in the garage I NEVER lock it

Don't want to find the battery flat when I need it

Is this really likely to be a problem?..